Study of Genetic Diversity of Thymus Pubescens using RAPD Marker

Aim and Thymus is one of the largest and the most famous genus of Lamiacae. Thymus species are commonly used as herbal tea, condiment, spice and medicinal plants. T.Pubescens most can be grown in north and west of Iran. Characterization of plants using molecular markers is an ideal approach for improvement and conservation of plant genetic resources. A total number of 12 accessions, collected from different localities of Iran, were screened with 30 random primers to evaluate polymorphism. DNA extraction carried out using Khanoja method with modification. Genetic similarity was estimated using the Jaccard coefficient and dendrogram was constructed using the UPGMA method. Selected 27 primers generated 360 bands, 273 of which were polymorphic. Each primer produced an average 13.33 bands per primer, of which 10.11 were polymorphic. The average of polymorphism information content (PIC) was 0.35. Cluster analysis of data using UPGMA algorithm placed the 12 accessions into three main clusters and the principal component analysis placed the 12 accessions into three groups. Results indicated that RAPD method is sufficiently informative and powerful to estimate the genetic diversity in T.Pubescens populations. In addition, RAPD profile showed well discrimination of thymus accessions according to their geographical dispersion.